Process of preparing diazo-types



Patented July 17, 1934 PATENT OFFICE PROCESS OF PREPARING DIAZO-TYPES Guy Grandsaignes DHauterive, St.-Denis, France, assignor to Kalle & Co. Akticngesellschal't, Wiesbaden-Biebricli, Germany No Drawingl Application November 4, 1932,

Serial No. 1931 6 Claims.

Photographic papers are known whose lightsensitive layer chiefly consists of a light-sensitive diazo compound. These known papers, after exposure to light under a pattern, yield pictures, if they are treated under suitable conditions with a solution of an azo component. This process of treating the pictures with a liquid developer involves, however, a great drawback in comparison with certain other papers which permit the production of pictures by the simple action of ammonia gas without the aid of any liquid.

The present invention relates to a process of preparing diazo-types. It comprises subjecting a material sensitized by means of a light sensitive tern or design and then causing the vapors of an aromatic amine, which is volatile to a'certain degree and capable of coupling with diazocompounds, to act upon the material thus treated. 2 According to this method a dyestuff is formed at those portions of the sensitive material which were not exposed to light. Thus a positive dyestufi picture is obtained from a positive design and vice versa. The after. treatment with the aromatic amine can he carried out'in different ways. The amine may be vaporized and the vaporsthus obtained act upon the exposure material. Or, the amine is dissolved in a suitable solvent, for instance alcohol, and a support, such as blotting paper, paper, tissue or the like is impregnated with this solution and, after evaporation of the solvent, brought in contact with the exposed material. Thereby, vapors of the amine rise from the impregnated support and act upon those portions of the diazo compound in the sensitive material which have not been destroyed by light. 1

The process according to this invention has the following advantages:

1. It permits the preparation in a-simple manner of the light-sensitive layer which, in principle, does not contain more than one diazo compound.

2. For the development there are used gaseous products which have not the odor of ammonia gas, since certain amines which can be utilized according to the process of this invention evolve practically odorless vapors.

3. The pictures can be developed by means of room and is quite economic, as itwill be described plates or the like.

aromatic dia'z'o compound to light under a pata simple apparatus, which does not take much.

641,321. In France November 9,

For preparing light-sensitive papers one of the following processes may, for instance, be utilized: On the paper there is applied a layer of a solution of the diazo compound in water or in a suitable more or less aqueous organic solvent and the o0 excess of liquid is removed, for instance by means of a doctor device, as it is usually done in the preparation of the so-called ferrocyanide papers; or, on the surface of the suitably pretreated paper there is applied a layer of a colloidal solution, for instance collodion, or a more or less aqueous gelatine solution, in which the lightsensitive diazo compound has been dissolved.

For the production of light-sensitive films for the process of the present invention one proceeds as follows: The film mass is impregnated with a solution of a diazo compound in a solvent which is capable of penetrating into the film mass; or there is applied on the film a solution of the diazo compound in a solvent, which vaporizes rapidly, but at the same time rapidly penetrates into the film; or there is applied on the film a colloidal solution, for instance collodion, or a more or less aqueous gelatine solution in which the light-sensitive diazo compound has been dissolved: or there is vaporized on a provisional support, for instance on a metal strap, a colloidal solution, for instance collodion, or a solution of methyloellulose, in which the light-sensitive diazo compound has been dissolved.

It is also possible to add to the light-sensitive diazo compound bodies, such as metal salts, which are capable of altering the shade of the dyestuffs obtained by the development or of forming with these dyestuffs insoluble colorlakes. It is furthermore'possible to add hygroscopic bodies, for instance glycerine or calcium chloride, which promote the development by retaining in the film or paper a rather large quantity of hygroscopic humidity.

Other products may likewise be added, which are destined to modify or ameliorate the proper-H ties of the pictures obtained or to increase the stability of the light-sensitive preparation, for instance organic acids. Products, such as thiourea, may also be added in order to preserve the pure whites or lights of the pictures.

As a solution for sensitizing paper or films from transparent regenerated cellulose there may be utilized, for instance, an aqueous solution containing 1 per cent of the diazo chloride obtained by diazotizing the hydrochloride of para-amino diphenyl-amine, 2 per cent of tartaric acid and 8 I per cent of glycerine. Generally, there may be used all diazo compounds usual in diazo-type- 110 a metal salts.

processes, such, for instance, as diazo compounds of aromatic diamines, ami'no-acylamines, aminophnylflhers and substitution products thereof.

'Thus the diaao-cornpounds of anisidine, dianisidine, aminodiethylaniline, amino-diphenyl-ether or similar products are suitable---for the new process.

The paper or him thus treated is exposed to light under a pattern, developed and fixed as follows: A strip of blotting paper or tissue has been impregnated with a 6 per cent alcoholic solution of an aromatic mono-or di-amine capable of coupling with diazo compounds and being volatile in a certain degree, such as alpha-naphthylamine or meta-toluylene-diamine having a considerable vapor tension at ordinary temperature; the said strips have been allowed to dry and a sort of book has been composed therefrom which is placed into a metal envelope. The prints to be developed are placed between the foils of the said book and left therein for a sumciently long time, for instance, for half an hour in the case of prints produced on the paper prepared as above described. Pictures are obtained which have a blue shade when alpha-naphthylamine has been used,

and a violet shade when meta-toluylene-diamine has been employed. According to the diazo compound used and the amine employed for the development there may be obtained the most varied shades varying from red and yellow .to black. The shades may furthermore be altered by utilizing two or more different diazo compounds and amine mixtures. The pictures may also be washed or subjected to an after treatment, such as is usual in diazotype printing, for instance with The action of heat and humidity increases the rapidity of 'the development. J

The application of pressure for producing an intimate contact between amine and light-sensitive preparation likewise accelerates the development. If all conditions remain unaltered, the rapidity of the development varies with the nature of the light-sensitive diazo-compound used and the amine applied. For a paper sensitized with the diazotization product of the hydrochloride of para-aminodimethylaniline the duration of development may, for instance, be reduced to 10 minutes or even less. i

The vapors of amines serving for the development may, of course, also be produced under other conditions, for instance in a heated vessel containing the amine or an alcoholic solution thereof. It is also possible to carry out a continuous dea machine comprising feedfeeding devices, consisting of cylinders coated with endless tissue or felt which has previously been impregnated with an amine.

Some'examples relating to the development of diazo-copies with amines are given below.

Examples 1. Cellulose foil is impregnated with a solution containing 1.2 parts by weight of diazodiphenylamine-sulphate, 20 parts by volume of glycerine, 1.5 parts by weight of citric acid in 90 parts by volume of water, and on this material copies in the following tints are obtained by the present process:

With m-toluylene diamine bluish violet,

With o-anisidine dish.

' 2. If cellulose foil is impregnated with a solution of 1.2 parts by weight of the zinc chloride double salt of the diazo-compound of p-aminodiethylaniline, 0.8 parts by volume of tartaric acid, and 20 parts by volume of glycol in parts by volume of water, olive green tints can be obtained with m-toluylene diamine and yellowish brown copies with m-aminophenol.

3. A nitrocellulose film provided with a layer of gelatine is impregnated with a solution of 2.5 parts by weight of the zinc chloride double salt of the diazo-compound of p-aminoethylbenzylaniline, 0.8 parts by volume of tartaric acid and 10 parts by volume of glycerine in parts byvolume of water. After exposing under an original copy and developing by the process described hereinbefore copies in'the following tints are obtained:

With m-toluylene diamine violet, With m-aminophenol brown, With mono-ethylaniline brownish, With a-naphthylamine brown.

violet copies and m-aminoph red copies.

I claim:

1. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under a pattern and then treatingit with the vapors of an aromatic amine capable of coupling with diazo compounds.

- 2. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under a pattern and then treating it with a dry support which has been impregnated with a volatile aromatic amine capable of coupling with diazo compounds.

3. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under a pattern and then treating it with vapors of alpha-naphthylamine.

4. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under a pattern and then treating it with a dry support which has been impregnated withalpha-naphthylamine.

5. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under .a pattern and then treating it with vapors of meta-toluylenediamine.

6. The process of preparing diazotypes which comprises exposing a material sensitized by means of light-sensitive aromatic diazo compounds to light under a pattern and then treating it with a dry support which has been impregnated with meta-toluylenediamine.

G UY GRANDSAIGNES D'HAU'I'ERIVE. 

